Automatically-rotating transparency-displaying lantern



.Baanrn 22 1924o 3,481,518

F. M L. LENNARD AUTOMATICALLY ROTATING TRANSPARENCY DISPLAYING LANTERN Filed Sept. 11. 1922 2 Sheets-Sheet 1 F. MOL. LENNARD AUTOMATICALLY ROTATING TRANSPARENCY DISPLAYING LANTERN 2 Sheti-Sheet 2 Filed Sept. 11.

a; I I fax swam- Willey/(2rd Patented den. 22, 122%.

an Mcnmman LENNY AUIQEEATIGALLY-ROTATING 1 a .4

, or nnamnenu warns, AUSTt' NEAR SYDNEY, Y m.

SPARMCY-IDEPLAYING MT Application filed September 11, 1922. Serial Kilo. 587,525.

To all whom e't may concern:

Be it known that I, FRANK MOLENNAN LENNARD, a subject of the King of Great Britain and Ireland, residing at 11 Crai end a Street, Darlin hurst, near Sydney, ew

1o specification.

South Wales, ustralia, have invented certain new and useful Improvements in Automatically-Rotating Transparency-Displaying Lanterns, of which the following is a This invention relates to illuminated display lanterns of the type in which an assemly of lantern slides or other prepared transparencies of pictorial or other display matter is held in a drum like carrier WhlCh is pivot mounted for rotation about a lamp disposed within it; in that type of lantern, rotative motion is applied to the carrier by convection air currents produced by heat from the lamp, which act on vanes fixed on the carrier structure; the slides or other transparencies are thus caused to be presented successively to the view of anobserver, or are projected serially upon a wall, screen, or other display surface.

The present invention consists in certain means for momentarily arresting the rotating motion of the carrier at intervals in order that the several slides or transparencies will be presented to view during dwells inthe rotative movement of the carrier; and it further consists in certain structural features of the carrier which are hereinafter particularly set forth.

The carrier is an open end vertically disposed drum-like structure. with a .belt of apertures around its lower portion; said apertures are provided with clips or slide holders for retaining a lantern slide or other transparency in each of them. In its upper part this drum carries an assembly of helical vanes symmetrically disposed in radial order and overlapping each other. These vanes support a tube axially within the drum, and a step bearing is fitted centrally in a bridge or cup in the top end of said tube; said bearing should be in the form of a jewel cup. It rests upona jewel point which is fixed in the top end of a post which is mounted on the top of an electric glow-lamp which is set in a socket on a fixed element and is disposed concentrically within the barrel with its filament in the locality of the horizontal plane of the slide apertures.

A ring which is fixed to a casing and encircles the drum forms a support for rotation arresting device. Said device consists in one or more (usually two). cruciform tappet weights which are hung from the fixed ring by swivels with their arms disposed in an horizontal plane. The arms of these tappet weights are engageable by striker pins whlch are fixed on and radiate from the drum sides. As the drum rotates under the propeller action of the air current which is caused to ascend through the drum by heat radiated from the lamp bulb, the striker pins come into contact with the arms of the pendent tappets. The drum ismornentarily brought to. rest when such contact occurs but the rotational movement recommences immediately the engaged striker pin is released by rotation and lateral swinging movement of the engaged tappet, which happens almost immediately; the tappet rotates and swings a little to offer the required clearance for the movement;

In the accompanyin drawings Fi 1V is a sectional e evational view showing t eapparatus arranged in a casing forthe exhibition of views by projection upon a ground lass screen, a lens cell being fixed in a diap ragm between the projector and the screen;

Fig. 2 is a top plan view of the lantern portion of the case shown in Fig. 1 in section-this view is taken on the section of line 22 Fig. 1; and

Fig. 3 is a vertical partial sectional elevation through the lamp.

In Fig. 1, 10 is a case divided into two (pmpartments by a diaphragm 11, in which a lens cell 12 is mounted. 1-3 is a ground lass screen carried in an aperture 1% in the ront end of the case compartment 15. The lantern 30 is erected in the case compartment l6. 17-18 are gratings permitting air circulation upwardly whilst protecting the lantern against interference and injury; 19 is a glow-lamp carried in the usual socket in a bracket 20, and 21 is a supply line of an electric service for providing current to the lamp 19. At the top end of the lamp 19 a post 22 is supported on spread legs 23 which are cemented vto the lamp bulb. 24 is a jewel point mounted in the top of the post 22, 25 1s a thin metal tube, 26 a bridge near the top endof same, and 27 a jewel cup in- 'said bridge adapted to seat on the jewel pivot point 24. he drum of the lantern 1s polygonal-as shown it is ten-sided each side being formed in the skirt or lower part with apertures 31 formed with guide lips 32 to ca lantern slides or other transparencies. he apertures 31 are located about the horizontal level of the center of illumination of the lamp 19. In its u per part the drum is fitted with an assembly of light sheet metal vanes 34 which are attached by lug ieces 35 passed through punch holes 111' t e drum body and closed over. These vanes 34 are helically disposed and overlap each other in the manner clearly seen 1n Fig. 2, they surround the tube 25 to which they are similarly attached by lugs 37 passed through punch holes and turned over in the manner shown. The vanes 34 thus form fins from which the lantern body is supported on the tube 25 so that the whole assembly is rotatable on the jewel-point 2 L. An upward current of air which is caused to ascend by heat radiated from the lamp 19 coacting on the vanes 34 applies rotative movement to the drum. From the body of the drum, at intervals thereon, striker pins 39 are fixed-five of such pins are shown. These pins coact with two tappets which function as temporary steps to arrest the rotative motion of the drum momentarily as each ofthem in turn is engaged by one of the striker pins 39. A pause or dwell is thus arranged at each one-tenth rotation of the drum. Consequently an onlooker is enabled to observe or read the transparency matter at ease as it is presented to him without movement for a short period as it passes his line of sight. In the case of a. projector arrangement such as shown in Fig. 1, the pause or dwell is essential in order to obtain positive projection of a picture on the screen 13; if the lantern were permitted continuous movement the views could onl be observed running which is the condi-tlon desired to be obviated. The tappets 50 are cruciform members having more or less weight according to the weight of the lantern structure; they are hung through swivels 51 from the ring 52 which is fixed to the door of the casing 10. They hang in the rotative path traversed by the strikers 39 so that in the rotation of a lantern they are engaged by the strikers; in such engagement the lantern is momentarily brought to a standstill, but is freed by the lateral swinging movement of the engaged tappet and by its rotation on its endent swivel 51. It is only necessary tl tat a positive momentary arrest of the movement of the lantern should be procured, as it is desirable that. the views exhibited should follow in sequence rapidly so long as a definite dwell occurs; as each slide or transparency comes into view the control of the continuous rotative movement of the mantis lantern which is 'procured by' the action of the convection air current on the vanes 34 converting it into an intermittent rotative movement is effected entirely automatically and without the use of gearing or mechanical elements, the loose tappets effectively performing the desired function. The number of tappets required is dependent upon the number of strikers provided, and the arrangement should be suchthat momentar arrest of the rotational movement of the lantern is procured for each particular exposure offered to observation.

\ The tappet element has a certain vis-inertia which is proportioned in relation to the impact of the striker upon it to permit it to be moved thereby to clear the striker, so that it functions to bring the carrier to rest or nearly to restwhen it is engaged by the striker but is retired immediately so as to free the striker and to permit the normal rotation of the carrier to be resumed.

What I claim as m invention and desire to secure by Letters atent is 2- 1. In a display lantern having a slide carrier and a lamp located within it with means dependent on convection air currents to procure rotation of said carrier, means for momentaril arresting the rotation of the carrier to 0 er a still view of the slides, consisting of one or more pendent tappets rotatably hung from. a fixed member in the path of movement of strikers fixed to the carrier and engageable by said strikers.

2. In a display lantern having a slide carrier and a lamp located within it with means dependent on convection air currents to procure rotation of said carrier, a device for interrupting the rotation of the carrier at uniform intervals comprising a tap-pet element having vis-inertia engageable by a striker at intervals during rotation of the carrier and arranged to be retired from the path of the striker during the period of contact thereby to free the parts immediately after arrest of the rotative motion of the carrier.

3. A display lantern comprising a polygonal open end rotatable drum vertically disposed With. slide apertures in its skirt portion, a glow lamp on a fixed socket to create convection air currents to rotate said drum,

a post mounted on the top of the glow lamp,

cally dispose polygonal open end drum lantern comprisinga vertiwith a, tubular axis in its upper pal-9 and strikers on t drum arranged to engage overlapping helically disposed vanes besaid tappets ing rotation of the drum, tween said drum and said tubular axis, a, substantially as illustrated in the aecoin- 10 post mounted on a fixed glow lamp with a, panying drawings.

5 point and cup bearing for said tubular axis, In testimony whereof I afiix my signature.

slide apertures in the drum skirt, pendent tappete hung from a. fixed support, and FRANK MOLENNAN LENNARD. 

